Mechanism for feeding and driving screws



United States Patent MECHANISM FOR FEEDING AND DRIVING SCREWS 7 Claims, 5 Drawing Figs.

US. Cl 144/32, 206/56 Int. Cl B25b 23/00 Field of Search 144/32; 206/56(DF) [56] References Cited UNITED STATES PATENTS 2,256,012 9/194] Blair l44/32 Primary Examiner-Gerald A. Dost Attorney-Joseph F. Cole ABSTRACT: A mechanism for feeding and driving screws in which an electric motor is used for rotating a screw driver, and a turret-type magazine is provided for holding screws in tubes, the housing of the motor having front and rear guide sleeves supported thereby that surround the screw driver, and gates are provided for feeding screws from a selected tube of the magazine into the front sleeve in a position forwardly of the kerf-engaging tip of the screw driver. the rear sleeve being movable forwardly over the front sleeve when the motor housing is pushed toward a selected member into which the screw is to be driven, thereby advancing the screw driver and rotating the latter.

Patented Sept. 1, 1970 INVENTORL JOSEPH T- KIRKL N ATTORNEY MECHANISM FOR FEEDING AND DRIVING SCREWS SUMMARY An object of this invention is to provide a mechanism for feeding screws from a turret-type magazine having a plurality of screw-feed tubes, the magazine being mounted to extend generally lengthwise of the screw driver, and a pair of gates are provided through which the screws pass into a front guide sleeve forwardly of the kerf-engaging tip of the screw driver. The latter may be advanced for driving the screws into selected members.

Another object of the invention is to mount the magazine for removal, whereby the tubes may be readily filled from their rear ends with a supply of screws, at which time the gates may be closed so as to prevent the screws from dropping out of the front ends of the tubes when the magazine is held in a vertical position.

A still further object of the invention is to provide an arrangement wherein the screws are precluded from jamming against one another as they are fed toward the front guidesleeve, and wherein a nose piece is buttable against the selected member into which the screws are to be driven, the nose piece having resilient fingers positioned to guide the screws forwardly.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention, reference should be made to the accompanying drawing, forming part of this specification, in which:

FIG. 1 is a side elevational view of my mechanism for feed ing and driving screws, parts being shown in section; 3 'FIG. 2 is an oblique view of a nose piece that is used for holding the screws in position as they are driven forwardly; 'FIG. 3 is a transverse sectional view taken along the plane 3- -"3ofFIG.I; FIG. 4 is an oblique view ofa pair of swingable gates; and

FIG. 5 is a transverse sectional view taken along the plane 5- "-5 of FIG. I.

I DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT j Referring now to the drawing, it will be noted that an electric motoi' A has been shown as having a housing in which an armature II and a stator I2 are mounted. It is conventional to provide a pistol grip I3 on the housing, and a trigger switch I4 controls the operation ofthe motor. The armature drives a pinion that meshes with a gear I6. Of course, I do not wish to be limited to any particular electric motor.

Asdisclosed in FIG. I, a screw driver B is secured to the gear I6for rotation by the motor, and the screw driver projects forwardly from the housing I0 and it has a kerf-engaging tip I7 at its front end. Moreover, a rear guide sleeve C is secured to the housing I0 and surrounds the back portion of the screw driver. Also, a front guide sleeve D is telescopically arranged in the rear guide sleeve, with the former movable into extended and retracted positions relative to the latter, the front sleeve surrounding the front portion of the screw driver B. A coil spring 18 is disposed in the sleeve C and bears against the back end ofthe sleeve D, biasing the front sleeve to its outward terminal position with respect to the rear sleeve.

A turret-type magazine E defines a plurality of screw-feed tubes mounted for rotation about the axis of a rod 20 extending lengthwise of the screw driver B, each tube being made to hold a series of screws 21 that are movable toward the front ends thereof for discharge of the screws, and these tubes are movable in succession into a lowermost position with respect to the magazine when the latter is turned.

For supporting the rod 20 at its back end a bracket 22 has been secured to the motor housing I0, while the front end of thisrod is threaded into a second bracket 23 secured to the front sleeve D. i

Referring to FIGS. 1, 3 and 4, a pair of swingable gates F are mounted over the front ends of the tubes 19 and each gate is formed with a notch 24. These gates are swingable about the front end part of the rod 20 into positions wherein their notches will be aligned with one another and will register with the lowermost tube 19, as disclosed in FIG. 3 by full lines, thereby permitting discharge of screws from this lowermost tube. At this time the gates F close all of the other tubes at their front ends.

As will be seen from FIGS. 1 and 3, the front guide sleeve D has a slot 25 through which a screw will fall from the gates F into the interior of this sleeve, and this slot is arranged forwardly of the normal position of the tip 17 of the screw driver B. The rear sleeve C is slidably in a forward direction on the front sleeve D against the action of the spring 18, when the housing 10 is pushed forwardly so as to advance the screw driver with its tip engaging in the kerf 26 of a leading screw 21a then disposed in the front sleeve, whereby this screw may be turned and driven forwardly.

The bracket 23 has apassage 27 through which a screw may descend to the slot 25. The next screw 2112 will be inclined downwardly as it enters the passage 27 and its head will abut the bracket 23 so as to retain this screw against jamming against the leading screw 21a. However, after the screw 21a has been driven forwardly and then the screw driver .B retracted, the next screw 21b may drop through the slot 25.

Each gate F is provided with a stop lug 28 disposed to bear against the front sleeve D when their notches 24 are aligned with one another and both register with the lowermost tube 19, as shown in FIG. 3.

The magazine E is removable and may be turned into upright position for filling the tubes 19 from their rear ends with a supply of screws. One of the gates F may be turned relative to the other gates so that their notches 24 are non-aligned,

as shown by dot-dash lines in FIG. 3, with the two gates form-:

ing a closure over the front ends of all of the tubes 19, thus preventing the screws from dropping out of the tubes during" against the shank of each screw as the latter is advanced by the screw driver B. This nose piece may be removably secured to the front sleeve D, and the fingers are made to yield as the head of the screw is pushed therebetween. Nose pieces of different sizes and shapes may be used, depending upon the particular type of screws being used. As shown in FIGS. 1 and 2, the nose piece G is provided with a raised pocket or dome 29a. at its top so that the shank ofthe next screw 21b may swing upwardly as the head of the leading screw 21a is advanced therebeneath, and this will prevent the screws from jamming. I

A circuit breaker 30 for the electric motor is mounted on the housing 10, and a push rod 31 is slidably guided in brackets 32 on the rear sleeve C and is engageable with the circuit breaker. The front sleeve D is provided with an adjusta ble stop bracket 33 disposed to engage with the push rod 31 to, open the circuit of the motor and stop the latter after the lead ing screw 2la has been advanced to a position where this screw about clears the nose piece G, or any desired position.

It will be apparent that the tubes 19 slope downwardly in a The selected member into which the screws are to be driven is designated at 36 in FIG. 1, and the nose piece G bears against the face of this member, thereby holding the front sleeve D from moving forwardly when the motor housing 10 is pushed forwardly so as to advance the screw driver B. This causes the rear sleeve to move forwardly relative to the front sleeve D.

In order to limit the forward extension of the front sleeve D relative to the rear sleeve C, the former has been provided with a pin or set-screw 37 that projects into an elongated slot 38 formed in the latter (see FIG. I). This pin and slot arrangement will prevent the front sleeve from rotating with respect to the rear sleeve, and thus the bracket 23 that is secured to the front sleeve will hold the magazine E above the screw driver B in the position illustrated.

lclaim:

1. In a mechanism for feeding and driving screws:

a. an electric motor having a screw driver secured thereto so as to project forwardly therefrom, the motor being operable to rotate the screw driver and the latter having a kerfengaging tip at its front end;

. a rear guide sleeve secured to the housing of the motor and surrounding the back portion of the screw driver;

. a front guide sleeve telescopically arranged in the rear guide sleeve, with the former being movable into extended and retracted positions relative to the latter, the front guide sleeve surrounding the front part of the screw driver;

d. a spring biasing the front sleeve to its terminal outward extended position with respect to the rear sleeve;

e. a turret-type magazine defining a plurality of tubes mounted for rotation about an axis extending generally lengthwise of the screw driver, each tube being made to hold a series of screws that are movable toward the front end thereof for discharge, and these tubes being rotatable in succession into a lowermost position with respect to the magazine;

f. a pair of swingable gates mounted over the front ends of the tubes, each gate being provided with a notch, and the gates being swingable into positions wherein their notches will be aligned with one another and will register with the lowermost tube for discharge of screws from the latter, at which time the gates close all of the other tubes at their front ends;

g. the front guide sleeve having a slot through which a leading screw will fall into the interior of the front sleeve, and this slot being disposed forwardly of the normal position of the tip ofthe screw driver; and

h. the rear sleeve being slidable in a forward direction on the front sleeve against the action of the spring when the motor housing is pushed forwardly so as to advance the screw driver, with its front tip engaging in the kerf of the leading screw then disposed in the front sleeve, whereby this screw may be turned and driven forwardly.

2. The mechanism for feeding and driving screws, as set forth in claim 1;

i. and in which each gate is provided with a stop lug disposed to bear against the front sleeve when their notches are arranged in alignment with one another and both notches register with the lowermost tube.

3. The mechanism for feeding and driving screws, as set forth in claim 1;

forth in claim 1;

i. and in which the tubes slope downwardly in a forward direction, whereby the screws will gravitate toward the gates.

5. The mechanism for feeding and driving screws, as set forth in claim 1;

i. and in which a nose piece is secured to the front sleeve and being provided with resilient fingers disposed to bear against the shank of the leading screw as the latter is driven forwardly so as to support this screw, these fingers being made to yield for passage of the screw head therebetween, 6. The mechanism for feeding and drtvmg screws, as set forth in claim 5;

j. and in which a bracket is secured to the front sleeve and is formed with a passage through which a screw may move from the gates toward the slot in the front sleeve, this bracket being positioned for abutment of the next screw thereagainst so as to hold this screw in a position wherein it will notjam the leading screw then in the front sleeve;

k. the nose piece being provided with a raised pocket so that said next screw may swing from an inclined position into an upper position as the leading screw is advanced therebeneath.

7. The mechanism for feeding and driving screws, as set forth in claim 5;

j. and in which a circuit breaker for the electric motor is mounted on the motor housing, and a push rod is slidahly guided on the rear sleeve and engageable with the circuit breaker, the front sleeve having a stop bracket disposed to engage with the push rod to open the circuit of the electric motor and stop the latter about the time the leading screw clears the nose piece, or any desired position. 

